The purpose was to temporarily, while you were in the bathroom, say what kind of bathroom it was.
If you don't care who else uses it while you're in there, dial "don't care". If a man dialed "women" and went in, he'd likely face some angry students. To my knowledge that never happened.
If you don't care who else uses it while you're in there, dial "don't care". If a man dialed "women" and went in, he'd likely face some angry students. To my knowledge that never happened.